Synthesis and Properties of Copolymers Based on Vinyl Chloride

Radical copolymerization of 1-vinylazoles with vinyl chloride and the composition and properties of the resulting copolymers were studied.__________Translated from Zhurnal Prikladnoi Khimii, Vol. 78, No. 4, 2005, pp. 647–651.Original Russian Text Copyright © 2005 by Shaglaeva, Lebedeva, Sultangareev, Trofimova.     

Studies in Vinyl Polymerization. Reinitiation by Allyl Chloride Transfer Radicals in the Polymerization of Vinyl Acetate

The kinetics of vinyl acetate polymerization in the presence of allyl chloride were studied by a dilatometric method. The retardation of the rate of polymerization was explained in terms of degradative chain transfer to allyl chloride. Analysis of the polymerization rate data indicates that a relatively large proportion of the allyl chloride transfer radicals is reactive toward initiation.     

A Model for the Emulsion Polymerization of Vinyl Chloride

Phenomena of emulsion polymerization of vinyl chloride have been analyzed on the molecular scale. A quantitative model is developed in which the polymerization is assumed to occur in a shell surrounding the dead core of the particles. The shell has the same composition as the entire particle, but it is assumed that the active species generated in the aqueous phase are not able to diffuse to the center of the particles and rather remain in a zone of limited thickness. Kinetic and geometric parameters are determined by fitting calculated values of rates and molecular weights to experimental data at 50°C.     

Properties of Crystalline Polyvinylenes Prepared by Phase-Transfer Dehydrochlorination of Vinyl Chloride Copolymers

Crystalline polyvinylenes were prepared by phase-transfer dehydrochlorination of binary copolymer of vinyl chloride with vinyl acetate (9 : 1 molar ratio) and ternary copolymer with vinyl acetate and vinyl alcohol (27 : 1 : 2 molar ratio), and the chemical and electrical properties of these substances and of products of their thermolysis were studied.     

Features of Radical Polymerization of Vinyl Chloride in the Presence of Nitroxyl Radicals

Radical polymerization of vinyl chloride in the presence of C-phenyl-N-tert-butylnitrone, 2-meth- yl-2-nitrosopropane, and 1-tert-butyl-3-phenyl-1-oxytriazene as potential sources of free radicals was studied.     

共聚物酸掺杂接枝聚苯胺的研究

采用核壳乳液聚合方法合成了以甲基丙酸甲酯、甲基丙烯酸和丙烯酸丁酯三元共聚物酸为核,聚苯胺为壳的导电高分子复合物。复合物的电导率随着聚苯胺含量的增加而升高。用粒径分析仪、ＴＥＭ、ＦＴ－ＩＲ和ＤＳＣ对复合材料进行了表征。结果表明形成了核壳结构,由于共聚物酸起到了掺杂剂的作用,使制得的复合物能在环己酮、四氢呋喃等普通有机溶剂中有好的溶解性。     

顶空气相法测定氯乙烯生产过程产生的盐酸溶液中的乙炔和氯乙烯

 采用顶空气相法测定了氯乙烯生产过程产生的盐酸溶液中的乙炔和氯乙烯。使用氢氧化钠将试样中的氯化氢中和 ,从而消除其在气相分析乙炔和氯乙烯中的影响。顶空平衡温度为 35℃ ,平衡时间为 4 5min ,柱为填充了GDX 2 0 2固定相的 2m× 3mmi d 不锈钢柱 ,柱温 14 0℃。顶空气体进样量为 1mL。以外标法定量 ,乙炔含量测定结果的相对标准偏差为 0 85 % ;当其含量为 30 0 μg/g～ 15 0 μg/g时 ,回收率为 98 9%～10 3%。氯乙烯含量测定结果的相对标准偏差为 1 4 % ;当其含量为 2 0 0 μg/g～ 10 0 μg/g时 ,回收率为 98 8%～10 2 %。     

Polymers and Copolymers of Vinyl Monomers with Blocked Isocyanate Groups: Synthesis and Characterization

Abstract

The polymerization of vinyl monomers containing blocked isocya-nate groups is reported. The blocking agents for the isocyanate groups of 2-isocyanato methacrylate were phenol, propanone oxime, benzophe-none oxime, and ecaprolactam. The ¹H-NMR and IR spectra of these polymers are discussed. Copolymerization reactivity ratios of the vinyl monomer blocked by phenol with styrene and methyl methacrylate have been determined. Glass transition temperatures of these polymers have been determined by differential scanning calorimetry. The homo– and copolymers were crosslinked in the presence of ethylene diamine, and the gels obtained were examined by IR spectra.     

Polymerization of Methyl Methacrylate in the Presence of Boroxyl Radicals. Synthesis of Block Copolymers

The kinetics of the radical polymerization of methyl methacrylate under the action of the amine–tripropylborane–oxygen system is studied at different borane : oxygen ratios in two modes: at direct contact between the polymerization mixture and oxygen and under the postpolymerization conditions, i.e., when, after brief contact, oxygen is removed from the system by vacuum pumping. It is shown that reversible-deactivation postpolymerization becomes possible when organoborane is in a twofold excess over oxygen. There were block copolymers of methyl methacrylate with styrene and acrylonitrile characterized under these conditions.     

聚氯乙烯和EVA树脂共混体系相容性的研究

用扭摆分析研究了EVA树脂和PVC共混体系中,VA含量和共混物组成对其相容性的影响.共混的两组分的分子间相互作用对其相容性有关键的影响.用FTIR测定羰基伸缩振动谱带的位移,可表征EVA-PVC分子链间的相互作用.     

An Approach to Disulfide Synthesis Promoted by Sulfonyl Chloride in Sodium Bicarbonate Aqueous Media

A mild and efficient protocol for the synthesis of disulfides in aqueous media using mercaptans promoted by sulfonyl chloride is reported. This reaction offers the advantages of mild reaction conditions, short reaction time, high yields, and simple operation.     

Notes: Polymer-Water Interaction in Emulsion Copolymerization of Vinyl Acetate

Abstract

In the case of copolymer latexes of vinyl acetate with maleic diesters, the amount of water bound to particles decreases with the increase of comonomer hydrophobicity. Increasing the concentration of bound water for more polar polymers determines a decrease of free water concentration. Therefore, the concentration of free surfactant and initiator in free water is higher and results in an increase of decomposition rate of potassium persulfate initiator. The increase of more polar copolymers hydration results in the increase of latex particle size.

     

Vinyl Polymerization. 386. Polymerization of Methyl Methacrylate Initiated by Imidazole in Aqueous Solution of Copper(II) Chloride

The radical polymerization of methyl methacrylate (MMA) was carried out with the system of imidazole (Im), copper(n) chloride, and water at 85°C. The effects of the amount of each component on the conversion of MMA were investigated. The polymerization proceeded through a radical mechanism. The overall activation energy was estimated to be 28.7 kJ/mole. The conversion of MMA showed a maximum at pH 8-9 of the aqueous solution. The formation of a complex of CuCl₂ with Im, water, and MMA was confirmed by electronic spectra. An initiation mechanism was proposed.     

Polymerization of Vinyl Chloride in the Presence of Alcohols

Precipitation polymerization of vinyl chloride in solution in the presence of alcohols was studied. The reaction mechanism was suggested, and the product composition was estimated by IR spectroscopy and selective extraction.     

Vinyl Polymerization. 418. Polymerization of Vinyl Monomer Initiated by Betaine-Type Polymers in Aqueous Solution

Abstract

Three kinds of betaine-type polymers, which are macromolecular amphoteric electrolytes, were found to be able to polymerize vinyl monomers in aqueous solution through a radical mechanism without any further initiator. Betain-type polymers form hydrophobic areas (HA) in water. Vinyl polymerization commenced in the HA. The effect of the pH of the aqueous solution on polymerization was investigated.     

超声辐照水体系下羟基自由基的检测

Fricke溶液在低频超声波辐照下产生羟基自由基,产生的羟基自由基可将溶液中的Fe2+氧化为Fe3+,用紫外-可见分光光度法测定Fricke溶液在235nm处的吸光度,根据吸光度变化值ΔA间接测定羟基自由基的产生量。初步研究了超声辐照时间、温度、频率和超声方式等因素对羟基自由基产量的影响。     

Solubility of Mannitol in Aqueous Sodium Chloride by the Isopiestic Method

Using a method for determination of solubilities of nonelectrolytes in electrolyte solutions based on isopiestic equilibration and precise chemical analyses, we have measured and report the solubilities of mannitol in sodium chloride solutions. Our results are, in general, in good agreement with the data of Kelly et al. The method is described and its advantages discussed.